60 gram. piperitone were added to a solution of 175 gram. ferric chloride, 160 c.c. glacial acetic acid, and 500 c.c. water. The whole was then heated on the sand bath to boiling. The action takes place according to the equation 2 FeCl3 + H2O = 2 FeCl2 + 2 HC1 + O, and was completed at the expiration of about one hour. The reaction product was then steam distilled, the phenol separated and absorbed in a 5 per cent. solution of sodium hydrate, the unabsorbed oil removed by ether, and the aqueous layer decomposed by hydrochloric acid. The phenol was then distilled under reduced pressure, when the thymol came over at 110-1110 C. at 10 millimetres. In this way a 25 per cent. yield of the weight of piperitone taken was recovered, but further researches will no doubt result in a much better yield being obtained. The thymol thus produced was identical in every way with the ordinary commercial article, and gave the chemical reactions for that substance.